I’m running on an MSI GT70 with a GTX675M discrete GPU.
I"m running ubuntu 14.10, and using the latest software from xorg-edgers ubuntu repository which includes nvidia driver 343.22.
I’ve found that randomly (I haven’t been able to find what triggers it) My display will lock up, and my fan will start spinning at maximum speed. I can ssh into the machine, and I’ve created the nvidia-bug-report. In addition I’m including the output from dmesg.